18-letter words containing a, c, r, o
- call to the colors — call or order to serve in the armed forces
- calliper compasses — an instrument for measuring internal or external dimensions, consisting of two steel legs hinged together
- cambrian mountains — a mountain range in Wales, extending from Carmarthenshire in the S to Denbighshire in the N. Highest peak: Aran Fawddwy, 891 m (2970 ft)
- camp david accords — a peace treaty between Israel and Egypt issuing from talks at Camp David between Egyptian President Sadat, Israeli Prime Minister Begin, and the host, U.S. President Carter: signed in 1979.
- cape breton island — an island off SE Canada, in NE Nova Scotia, separated from the mainland by the Strait of Canso: its easternmost point is Cape Breton. Pop: 132 298 (2006). Area: 10 280 sq km (3970 sq miles)
- carbonic anhydrase — an enzyme in blood cells that catalyses the decomposition of carbonic acid into carbon dioxide and water, facilitating the transport of carbon dioxide from the tissues to the lungs
- carbonic-anhydride — carbon dioxide.
- carboxyhaemoglobin — haemoglobin coordinated with carbon monoxide, formed as a result of carbon monoxide poisoning. As carbon monoxide is bound in preference to oxygen, tissues are deprived of oxygen
- carcinoid syndrome — the systemic effects, including flushing, palpitations, diarrhea, and cramps, resulting from increased blood levels of serotonin secreted by a carcinoid.
- career development — a progression through a series of jobs, each with more responsibility and a higher income than the last
- carisbrooke castle — a castle near Newport on the Isle of Wight: Charles I was held prisoner here from 1647 until his execution in 1649
- carolina chickadee — a chickadee, Parus carolinensis, of the southeastern U.S., resembling but smaller than the black-capped chickadee.
- carolina jessamine — a vine, Gelsemium sempervirens, of the southern U.S. and Central America, of the logania family, having glossy, lance-shaped leaves and fragrant yellow flowers: the state flower of South Carolina.
- carpenterworm moth — any moth of the family Cossidae, as Prionoxystus robiniae of the U.S. and southern Canada, whose larvae bore into the trunks and branches of oaks, locusts, and other trees.
- cartilaginous fish — any fish of the class Chondrichthyes, including the sharks, skates, and rays, having a skeleton composed entirely of cartilage
- cash-for-questions — of, involved in, or relating to a scandal in which some MPs were accused of accepting bribes to ask particular questions in Parliament
- cassiopeia's chair — the five brightest stars in the constellation Cassiopeia that seem to form the shape of a W or M
- castration complex — an unconscious fear of having one's genitals removed, as a punishment for wishing to have sex with a parent
- cat's cry syndrome — a complex of congenital malformations in human infants caused by a chromosomal aberration and in which the infant emits a mewing cry.
- catalogue raisonne — a descriptive catalogue, esp one covering works of art in an exhibition or collection
- catastrophe theory — a mathematical theory that classifies surfaces according to their form
- catch one's breath — When you catch your breath while you are doing something energetic, you stop for a short time so that you can start breathing normally again.
- categorial grammar — a theory that characterizes syntactic categories in terms of functions between classes of expressions. The basic classes are names (N) and sentences (S). Intransitive verbs are symbols for functions which take a name and yield a sentence (written S/N), adverbs form compound verbs from verbs (for example, run fast) and so are (S/N)/(S/N), etc
- catherine of siena — Saint. 1347–80, Italian mystic and ascetic; patron saint of the Dominican order. Feast day: April 29
- cathode dark space — Crookes dark space.
- cationic detergent — a type of detergent in which the active part of the molecule is a positive ion (cation). Cationic detergents are usually quaternary ammonium salts and often also have bactericidal properties
- cauliflower cheese — a dish of cauliflower with a cheese sauce, eaten hot
- cauliflower fungus — a large edible white to yellowish cauliflowerlike mushroom, Sparassis radicata, widely distributed in North America.
- ceiling decoration — a plaster moulding for the centre of a ceiling; other decoration, such as coving
- cellular automaton — (algorithm, parallel) (CA, plural "- automata") A regular spatial lattice of "cells", each of which can have any one of a finite number of states. The state of all cells in the lattice are updated simultaneously and the state of the entire lattice advances in discrete time steps. The state of each cell in the lattice is updated according to a local rule which may depend on the state of the cell and its neighbors at the previous time step. Each cell in a cellular automaton could be considered to be a finite state machine which takes its neighbours' states as input and outputs its own state. The best known example is J.H. Conway's game of Life.
- cellular telephone — a mobile phone
- central government — the government of a state or country
- central projection — a projection of one plane onto a second plane such that a point on the first plane and its image on the second plane lie on a straight line through a fixed point not on either plane.
- centralized school — a public school formed from the pupils and teachers of a number of discontinued smaller schools, especially in a rural district.
- cerebral dominance — the normal tendency for one half of the brain, usually the left cerebral hemisphere in right-handed people, to exercise more control over certain functions (e.g. handedness and language) than the other
- cerenkov radiation — radiation emitted when a charged particle travels through a medium at a speed greater than the speed of light through that medium
- certification mark — a mark that certifies the origin, material, quality, mode of manufacture, accuracy, or other characteristic of a product or service: “UL” is a certification mark for appliances meeting the safety standards of Underwriters Laboratories, Inc.
- cesarean (section) — a surgical operation for delivering a baby by cutting through the mother's abdominal and uterine walls
- chagos archipelago — group of islands in the Indian Ocean 1,180 mi (1,899 km) northeast of Mauritius, comprising the British Indian Ocean Territory: chief island, Diego Garcia
- chamber of horrors — a room, for example in a waxworks, containing objects, images or representations of people or scenes that are believed likely to frighten or horrify visitors
- character disorder — a disorder characterized by socially undesirable behavior, as poor control of impulses or inability to maintain close emotional relationships, and by absence of anxiety or guilt.
- character encoding — (character) (Or "character encoding scheme") A mapping between binary data values and character code positions (or "code points"). Early systems stored characters in a variety of ways, e.g. four six-bit characters in a 24-bit word, but around 1960, eight-bit bytes started to become the most common data storage layout, with each character stored in one byte, typically in the ASCII character set. In the case of ASCII, the character encoding is an identity mapping: code position 65 maps to the byte value 65. This is possible because ASCII uses only code positions representable as single bytes, i.e., values between 0 and 255. (US-ASCII only uses values 0 to 127, in fact.) From the late 1990s, there was increased use of larger character sets such as Unicode and many CJK coded character sets. These can represent characters from many languages and more symbols.
- charge conjugation — the mathematical operation of replacing every elementary particle by its antiparticle. Symbol: C.
- charge of quarters — a member of the armed forces who handles administration in his or her unit, esp after duty hours
- chartered surveyor — (in Britain) a surveyor who is registered with the Royal Institution of Chartered Surveyors as having the qualifications, training, and experience to satisfy their professional requirements
- check verification — Check verification is a system that checks national databases of information about individuals to make sure that checks will be honored and fraud is not being committed.
- checkpoint charlie — a crossing between East and West Berlin during the Cold War
- chew someone's ear — to reprimand severely
- children of israel — the Jews; Hebrews
- chinese watermelon — a tropical Asian vine, Benincasa hispida, of the gourd family, having a brown, hairy stem, large, solitary, yellow flowers, and white, melonlike fruit.